Phase change materials (“PCM”) have been added to compositions for a number of years, predominantly in the field of thermal energy storage. For example, Chahroudi et al., in U.S. Pat. No. 4,259,401, discloses both structural and non-structural building products incorporating phase change materials. These products are made of a rigid porous matrix structure that is impregnated with the phase change material or which may otherwise contain the phase change material. Three classes of phase change materials are disclosed by Chahroudi et al.: hydrated salts; waxes; and clathrates. Cements, plasters or thermosetting materials are said to be able to form the rigid matrix.
Salyer in a number of patents discloses materials for use in thermal energy storage in buildings. For example, U.S. Pat. No. 4,797,160 issued to Salyer describes compositions for use in thermal energy storage of buildings which contain crystalline, straight chain, alkyl hydrocarbons as phase change materials. The materials of Salyer include cementitious compositions containing the alkyl hydrocarbons neat or in pellets or granules formed by incorporating the alkyl hydrocarbons in polymers or rubbers; and polymeric or elastomeric compositions containing alkyl hydrocarbons.
Salyer in U.S. Pat. No. 5,053,446 discloses a composite said to be useful in thermal energy storage. The composite is formed of a polyolefin matrix having a phase change material such as a crystalline alkyl hydrocarbon incorporated therein and the polyolefin is thermally form stable. The composite of Salyer is said to be useful in forming pellets, sheets or fibers having thermal energy storage characteristics.
U.S. Pat. No. 5,565,132 issued to Salyer describes a thermoplastic, moldable, non-exuding phase change material in the form of a composite useful for thermal energy storage. The composite is said to be preferably a solidified melt mixture of a polyolefin resin, and ethylene copolymer, silica particles and a fatty acid, fatty acid ester, primary alcohol or hydrocarbon phase change material. For a microwave heating capability, a microwave absorbing additive may be added as a fifth major ingredient. The composite of Salyer is said to be able of being formed into a variety of configurations such as pellets, sheets, rods, tubes, plugs for hollow core cement blocks, films, and fibers, all for thermal energy storage uses.
Salyer in U.S. Pat. No. 5,885,475, describes a fiber composition made of a fiber forming polymer and a phase change material integrally incorporated throughout the fiber forming polymer which is either a polyalkylene oxide, polyalkylene ether or mixture of various polyolefins.
U.S. Pat. No. 6,265,457, issued to Dolgopolsky et al., discloses an isocyanate-based polymer foam matrix having disposed therein a particulate material having an enthalpy of endothermic phase transition of at least about 50 J/g. The particulate material is said to act as a heat sink and undergo an endothermic phase change by absorbing a significant portion of the heat of reaction liberated during the process of producing the foam. This heat absorption is said to improve the safety of the process by lowering the maximum exotherm experienced by the foam. There is no teaching or suggestion of utilizing the material of Dolgopolsky et al. with other polymers.
Wolf, in EP 1 493 777 A1, discloses a material for molded articles made of a polymeric base material mixed with porous particles of a filler, the cavities of which are filled with a phase transfer material. Also disclosed by Wolf is a process for the production of the molded article by filling porous particles with phase transfer material, introducing the particles into a polymer and processing the material by injection molding, extrusion, foaming or forming into textiles or other structures.
A web page that may be found at http://www.acmanet.org/bsa/overview-materials.cfm and entitled “Boy Scouts of America Composites Merit Badge-Overview of composite materials” lists a number of inert fillers that may be added to modify the properties of resins and reduce cost. Among those fillers on the list which includes everything from minerals to walnut shells to corn cobs, is “Thermoplastic spheres”. However, no guidance is provided as to how to select the proper filler to modify the desired property.
A copending, U.S. patent application Ser. No. 11/257,226, commonly assigned to one of the present assignees describes infrastructure repair and geo-stabilization processes with a low-exotherm polyurethane foam, grout or elastomer containing an organic particulate material capable of absorbing heat. There is no teaching or suggestion of utilizing that organic particulate material with polymers other than polyurethane.
Thermosetting polymers are commonly found in grouts, molded parts, void-filling materials, concrete-anchoring materials and castings. Because such materials are used and/or produced in places where the buildup of heat could not only be undesirable, but in some cases may be potentially dangerous, a need exists in the art for compositions such as polymer grouts, molded plastic parts, void-filling plastic materials, concrete-anchoring materials and polymeric castings that reduce the generation and accumulation of heat.